#include<stdio.h>
int main ()
{
	int sum;
	char a[100];
	int i,j;
	int countR;
	int countY;
	while(scanf("%d",&sum)!=EOF)
	{
		if(sum==0)
		{
			return 0;
		}
		getchar();
		//printf("Hello\n");
		gets(a);
		countR=0;
		countY=0;
		for(i=0; a[i]!='\0'; i++)
		{
			if(a[i]=='R')
			{
				countR++;
			}
			if(a[i]=='Y')
			{
				countY++;
			}
		}
		if(a[sum-1]=='B')
		{
			if(countR==7)
			{
				printf("Red\n");
			}
			else
			{
				printf("Yellow\n");
			}
		}
		if(a[sum-1]=='L')
		{
			if(countY==7)
			{
				printf("Yellow\n");
			}
			else
			{
				printf("Red\n");
			}
		}
	}
	return 0;
}
